Smart Evaluation Index of Roof SHS Suitability
Round 1
Reviewer 1 Report
This article proposes a simple index of “F,Q” to judge the suitability of the solar heating system built on the roof. Various heating cases of office buildings and three-star hotels were simulated to fit the regression models, which gives good prediction of solar energy guarantee rate. The index and models are of good exactness and simple in use. Couple of issues need to be addressed before I can recommend publication of the article:
(1) It seems that the fitting results of the area ratio “F” using logarithmic regression formula model is not very ideal (R-square < 0.99 in some cases). Did the authors try other regression models for comparison?
(2) The authors used index “F” to verify the solar energy guarantee rate in Ref. 20 and obtained 71.2% that agrees well with the measured value of 70%. However, it would be better to evaluate more actual cases use both “F” and “Q” to confirm the availability of the index and the models proposed in the article.
Author Response
Response Letter
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The authors would like to take this opportunity to express our sincere appreciation to the reviewers and editor for their positive evaluation and useful comments that allow us to make further modification to the paper
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Reviewer 1
This article proposes a simple index of “F,Q” to judge the suitability of the solar heating system built on the roof. Various heating cases of office buildings and three-star hotels were simulated to fit the regression models, which gives good prediction of solar energy guarantee rate. The index and models are of good exactness and simple in use. Couple of issues need to be addressed before I can recommend publication of the article:
(1) It seems that the fitting results of the area ratio “F” using logarithmic regression formula model is not very ideal (R-square < 0.99 in some cases). Did the authors try other regression models for comparison?
Response:
When fitting the area ratio "F", the fitting result of the logarithmic regression model has become the optimal solution. Although in some cases the result of the fitting is its R2< 0.99, but the author thinks that this method still has high reference value in practical application.
(2) The authors used index “F” to verify the solar energy guarantee rate in Ref. 20 and obtained 71.2% that agrees well with the measured value of 70%. However, it would be better to evaluate more actual cases use both “F” and “Q” to confirm the availability of the index and the models proposed in the article.
Response: Completed.
Additional experimental the validation data has been added in Line 332-347, Page 11 according to the references of [24] and [25].
Reviewer 2 Report
This study puts forward “F, Q” as the basis for judging the suitability of solar heating systems built on the roof. Two types of public buildings, office building and three-star hotel, are taken as the research objects. DeST software is used to change the heating area of the building by superimposing floors to simulate the heat load of the building when the heating area changes. A dynamic simulation coupling model of solar heating system is established in the TRNSYS software to analyze the operating status of the system under all working conditions.
This paper is very interesting and contains sufficient novelty in the field of solar heating system and energy consumption condition. Given the novelty and the contents of this paper, I’d like to recommend a minor revision to this submission to possibly improve the paper quality.
- The abstract is not well presented since only qualitative results are reported. Authors should also add quantitative results to highlight their contributions.
- The introduction part should be revised to enhanced the readership between engineering and Energies journal. More recently published journal papers in the field of solar energy and thermal energy storage applications should be given commented, such as Renewable Energy 2021, 172, 57-70; Applied Energy 2020, 279, 115772; Renewable Energy 2022, 183, 406-422.
- Figure 1 should be revised to be a high-resolution figure.
- Detailed descriptions on the experimental measurement for validating the current model should be added. And the possible reasons for the deviation between the current study and the data in literature should also be commented on.
- Four cities are selected for comparison. Could the authors explain the reason why these four are selected for study?
- For models (4) and (5), when fitting with experimental data, the relative error should be added to the coefficients in these two equations.
- For part 5, the results and discussion part should be put in section 4. For this part, a short summary of the current work with core points as conclusions may be more suitable for this paper.
Author Response
Response Letter
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The authors would like to take this opportunity to express our sincere appreciation to the reviewers and editor for their positive evaluation and useful comments that allow us to make further modification to the paper
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Reviewer 2
This study puts forward “F, Q” as the basis for judging the suitability of solar heating systems built on the roof. Two types of public buildings, office building and three-star hotel, are taken as the research objects. DeST software is used to change the heating area of the building by superimposing floors to simulate the heat load of the building when the heating area changes. A dynamic simulation coupling model of solar heating system is established in the TRNSYS software to analyze the operating status of the system under all working conditions.
This paper is very interesting and contains sufficient novelty in the field of solar heating system and energy consumption condition. Given the novelty and the contents of this paper, I’d like to recommend a minor revision to this submission to possibly improve the paper quality.
- The abstract is not well presented since only qualitative results are reported. Authors should also add quantitative results to highlight their contributions.
Response: Completed.
A description of quantitative results has been added to the abstract in Line 21-25, Page 1.
- The introduction part should be revised to enhanced the readership between engineering and Energies journal. More recently published journal papers in the field of solar energy and thermal energy storage applications should be given commented, such as Renewable Energy 2021, 172, 57-70; Applied Energy 2020, 279, 115772; Renewable Energy 2022, 183, 406-422.
Response: Completed.
References [7-9] in the field of solar energy and thermal energy storage applications have been added in Line 52-54, Page 2.
- Figure 1 should be revised to be a high-resolution figure.
Response: Completed.
Figure 1 has been revised to be a high-resolution figure.
- Detailed descriptions on the experimental measurement for validating the current model should be added. And the possible reasons for the deviation between the current study and the data in literature should also be commented on.
Response: Completed.
Detailed descriptions on the experimental validation have been shown in Line 330-345, Page 11.
The possible reasons for deviations between the current study and the data in literature are analyzed in Line 346-354, Page 11.
- Four cities are selected for comparison. Could the authors explain the reason why these four are selected for study?
Response:
Resource-Richer area, The Resource - rich area, The Resource - general area, Resource-poor area (proposed at the beginning of section 2.1) are divided according to "Technical Standards for Solar Heating Engineering". The selected four cities represent the four regions of different levels of solar energy abundance.
- For models (4) and (5), when fitting with experimental data, the relative error should be added to the coefficients in these two equations.
Response: Completed.
The standard errors in the regression analysis have been added to Tables S1, Page12, and Tables S3, Page 13.
- For part 5, the results and discussion part should be put in section 4. For this part, a short summary of the current work with core points as conclusions may be more suitable for this paper.
Response: Completed.
The discussion part has been put in section 4.4 in Line 355, Page 11.
The conclusion has been modified in Line 391-401, Page 12.
Author Response File: 
Author Response.docx
Reviewer 3 Report
This manuscript deals with evaluation of efficiency of roof solar
heating systems. The author propose two criteria; one is the ratio of
the total heat collected by solar collector to the heat load of
building, "Q", and the other is the ratio of the effective area of
solar collector to the heating area of the building, "F". Models are
established by DeST (Designer's Simulation Toolkit) software and
transient simulations are carried out using TRNSYS software. Office
buildings and the buildings of three-star hotels in different cities
China are examined. There is, however, no significant novelty in the
proposed indexes, "Q" and "F". Theoretical backgrounds are very poor
in the functions of the regression curves. The discussion of
correlations between the numerical results and these theoretical
curves stays in a level of practice exercises in a class. The
findings seem not to be useful for the readers of the journal,
Energies.
Author Response
Response Letter
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The authors would like to take this opportunity to express our sincere appreciation to the reviewers and editor for their positive evaluation and useful comments that allow us to make further modification to the paper
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Reviewer 3
This manuscript deals with evaluation of efficiency of roof solar heating systems. The author propose two criteria; one is the ratio of the total heat collected by solar collector to the heat load of building, "Q", and the other is the ratio of the effective area of solar collector to the heating area of the building, "F". Models are established by DeST (Designer's Simulation Toolkit) software and transient simulations are carried out using TRNSYS software. Office buildings and the buildings of three-star hotels in different cities China are examined. There is, however, no significant novelty in the proposed indexes, "Q" and "F". Theoretical backgrounds are very poor in the functions of the regression curves. The discussion of correlations between the numerical results and these theoretical curves stays in a level of practice exercises in a class. The findings seem not to be useful for the readers of the journal,Energies.
Response:
Dear editor, the "F and Q" proposed in this paper are two evaluation methods for evaluating whether the building is suitable to adopt solar heating system based on the understanding of relevant empirical formulas in "Technical Code for Solar Heating Engineering".
Through reading a large number of literature, most of the domestic and foreign researches on this aspect are to evaluate and improve the suitability of the solar heating system that has been put into use in existing buildings. Few people have analyzed buildings that have not yet used solar heating systems to determine whether they are suitable for solar heating systems. And, for now, want to get an accurate the result of the contribution rate of solar heating system needs in the practical engineering of existing buildings and solar heating system of multiple parameters measured and calculated (include: construction of indoor and outdoor temperature, the temperature of the import and export of solar collector/flow rate and water temperature of the heat storage tank and other related parameters), the process is relatively complex and burdensome. In reality, taking "F" as an example, it is easier to measure and calculate the heating area of a building and the effective area of the collector that can be arranged.
The method presented in this paper serves as a tool for assessing the suitability of solar heating systems. In the actual application process, the corresponding "F, Q" values can be obtained only by simple measurement and calculation. Then use the method to make a preliminary evaluation and prediction of the contribution rate of the solar heating system in the building, as a reference standard for the application value of the solar heating system in the building. Therefore, the author believes that although the mathematical tools used in this study are relatively simple, the proposed evaluation method is of great practical significance and application value.
Author Response File: Author Response.docx
